Does IS help with slow moving subjects?

The question the OP asked was:  is there any benefit to using IS when subjects are moving slow.  You people are focusing in on only one aspect of shooting - how to freeze subject motion blur.  What you are ignoring is:  in the types of motion we're talking about, you can freeze them with shutter speeds around 1/80-1/100.  If you're using a telephoto lens at those shutter speeds, you can still have camera shake.

In that situation, IS absolutely helps the photographer because it prevents camera shake.

Two different types of blur - shutter speed stops motion blur, IS stops camera shake.  In the real-world examples we're talking about, both types of blur can occur.  And IS can absolutely help with the camera shake.

The OP did NOT ask:  will IS stop motion blur.

The OP asked: Can it help with slow moving subjects.  And, in the real world it can.  By stopping the camera shake that can occur when you're shooting at shutter speeds fast enough to stop motion blur but still too slow to prevent camera shake.

Let's take this shot:  85mm at 1/40 a second of a jazz musician.

Now, no IS used here - but I'm pretty steady and it's only an 85mm lens.  Take this shot wiith a heavy 200mm lens at 200mm instead and there'd be more camera shake.  anti-shake would absolutely help.  So, we have a slow moving subject and 1/40 was enough to stop the slow motion of the subject but certainly not enough to stop camera shake with a heavy lens. anti shake would HELP - that's what the op asked.